Your knowledge vault, in the browser.
websidian is an open-source, privacy-first knowledge vault you reach from any browser. Take notes, organize nested folders, sketch with Excalidraw and read PDFs — all online, with nothing to install. Everything is end-to-end encrypted in your browser, so only you can read your vault — not even the server can.
4 registration spots remaining — capacity is limited while we scale.
Why websidian — and what it is not
websidian is an independent open-source project. It is not the original Obsidian (obsidian.md), not affiliated with it, and not a competitor. The name only describes the idea: an Obsidian-style markdown vault you open in any browser.
The original Obsidian keeps notes locally on each device and relies on a sync service to keep them aligned. In many companies you simply cannot install private sync clients or extra apps on enterprise laptops — so that setup is impossible. A browser is almost always available, so your vault stays reachable. Nothing to install, no local storage used on your phone or PC, and no encrypted backups for you to manage.
It is intentionally simple — just what you need in daily work and private life. The human brain is made for having ideas, not for holding them. This is your second brain.
How it differs from obsidian.md
The original Obsidian is a great desktop app that keeps your notes offline on each device and relies on a sync service to keep them in step. websidian flips that around: your vault lives online, end-to-end encrypted, and you simply log in with 2FA.
Nothing to sync
There is no sync to set up or pay for. Your notes are always in one place — log in from a laptop, PC or phone and pick up exactly where you left off.
Browser-native
Built for the cloud and the browser instead of an offline desktop install. Open a tab on any device and your full vault is there.
Account-based & secure
Access is protected by your account with required two-factor authentication (2FA). Privacy comes first — no tracking, no analytics.
Zero-knowledge encryption
Your notes, drawings and files are encrypted in your browser with AES-256-GCM. The server only ever receives ciphertext, so nobody — not even us — can read your vault.
Open source
The full source code is public. Use the hosted version or self-host it yourself from the published container image.
Features
All the everyday building blocks you need available online.
- Markdown notes with live preview
- Nested folders to organize your vault
- Wiki-style links between notes
- Web link manager — save & reopen trusted links
- Kanban boards — plan visually, cards link to your notes
- End-to-end encrypted chat — send files & whole folders that save straight into your vault
- Excalidraw drawing integration
- Built-in PDF viewer
- EPUB e-book reader
- Attachments & file uploads
- Full-text search that runs in your browser
- Export your whole vault as a decrypted zip
- Two-factor authentication (2FA)
- Zero-knowledge end-to-end encryption
- Recovery key to restore access if you forget your password
- Light & dark themes
Zero-knowledge by design
Your vault is encrypted and decrypted entirely in your browser. Your password never leaves your device, and the server only ever stores ciphertext it cannot read.
Only you hold the keys
Your encryption key is derived from your password in your browser and is never sent to the server. We physically cannot read your notes, drawings or files.
Keep your recovery key safe
When you sign up you receive a one-time recovery key. It is the only way back in if you ever forget your password. Store it somewhere safe.
Lost password, lost data
Because nobody but you can decrypt your vault, we cannot reset your password for you. If you lose both your password and your recovery key, the data is gone for good.
Ways to run websidian
Three ways to run it, all the same end-to-end encrypted vault. Pick how much infrastructure you want to look after yourself.
Your storage, your choice
Everything is end-to-end encrypted before it leaves your browser, so whichever storage you pick only ever holds ciphertext it cannot read.
websidian is a non-profit open-source project. Donations are voluntary and only help cover server costs — there is nothing to buy.
Ready to start?
4 registration spots remaining — capacity is limited while we scale.